What is the Gut-Brain Axis, Anyway?

Understanding the link between gut microbiota and mental health issues.

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Though seemingly not the sexiest part of the human anatomy to talk about, the gut is our body’s largest microbiome and its state of health has a huge impact on both physical and cognitive functions. A huge proportion of our immune system resides in our gut, where factors such as stress, pollution, antibiotics and poor diet can create an imbalance in the good bacteria.

Key indicators of disruptions in our gut health go beyond the mere physical, such as chronic digestive problems and fatigue. Brain fog, memory problems, anxiety, depression and even low sex drive can also be put down to this. When we think about it, it’s not that surprising that microbes have such a profound influence on us. After all, they greatly outnumber the human cells in our body by 10 to 1.

The gut is also home to around one hundred million neurons and the tissue which lines your intestines has a whole system of neurotransmitters which are connected to the brain via the vagus nerve. The vagus nerve is like a communication highway between your gut and brain. This back and forth discourse is what is referred to as the gut-brain axis and because of this connection, your memory and learning are affected when the microflora in your microbiome are out of balance.

The gut-brain axis has been acknowledged by ancient healing practices such as Ayurveda and Chinese medicine for thousands of years, but Western medicine is only just catching up. With more research that’s being carried out in this area, there is growing evidence that gaining a better understanding of the gut-brain axis and our gut microbiota in general will help psychiatrists and psychotherapists create radical new treatments for mental health issues such as anxiety and depression. So far, the majority of tests to date have been in mice, so plenty of further human studies are required in order to truly determine how and why bacteria-based interventions can have a positive effect on mental health. We’re looking forward to seeing how this medical research progresses.

Interested in learning more? Here are our top three book suggestions:

Gut: The Inside Story of Our Body's Most Underrated Organ, by Giulia Enders

This book is written in such a way that it makes you feel like your gut is an old friend. It’s simple, funny and charming, but also really educational too. Plus, we love a book with illustrations.

The Mind-Gut Connection, by Emeran Mayer

Despite being hefty in cutting-edge neuroscience, this book is a practical guide that’s easy enough to follow for those of us who didn’t graduate from med school.

Brain Maker: The Power of Gut Microbes to Heal and Protect Your Brain for Life, by David Perlmutter and Kristin Loberg

One of the most insightful things we learned from this book is that the microbiome develops from birth and evolves based on the environment we grow up in. So both nature and nurture have a part to play in our gut health.